1. Field of the Invention
The present invention is directed towards a method of structuring an electronic component which does not require manual tuning or alignment during its manufacture, wherein the component may include, but is not limited to, an equalizer which compensates for varying degrees of cable loss in CATV/MATV broadband network facilities. A trial and error procedure is implemented which includes applying a plurality of circuit modifications to a base circuit in an effort to initially approximate stabilization of signal characteristics of a signal being continuously processed through the base circuit and monitoring the signal characteristics to determine the effect of applying the approximating circuit modifications.
2. Description of the Related Art
In the communication industry, a cable television/master antenna television (CATV/MATV) broadband network collects available intelligent information from a variety of sources including antennas, satellite receivers, local originating signals, phone lines, and/or return paths of the broadband network in two-way operational networks. It is of course well recognized that CATV/MATV broadband networks utilize vast quantities of coaxial cable to establish and transmit such collected information. The frequency spectrum for these broadband networks usually range from 5 to 450, 550, 750, 860, or 1000 MHZ. Each signal is given a specific frequency in the network spectrum. The transmitted or processed signals as well as the collected information are combined for transmission onto a coaxial cable to be distributed throughout the CATV/MATV broadband network.
More specifically, operational details of this type of broadband network comprise the connection of the coaxial cable to lasers for transmission of the combined signal/information over fiber optics and the further transmission and/or amplification onto other coaxial cables by known passive or active methods. Finally, the collected signals are routed to the subscriber by means of fiber optics and cables, which are commonly referred to as the xe2x80x9ctrunkxe2x80x9d or xe2x80x9cback bonexe2x80x9d of the feeder system. The feeder system comprises a variety of different broadband components, which include coaxial cables, multiple port taps, amplifiers, splitters, attenuators and equalizers. The feeder system then distributes the intelligent information, using coaxial cable, to the subscribers or end users of a CATV/MATV broadband network.
One of the most common and problematic occurrences involved with the use of extended lengths of coaxial cable, in the manner set forth above, is the existence of xe2x80x9ccable lossxe2x80x9d. Such losses deteriorate transmission of information to the subscriber or end user as well as derogatorily effect the trunk and feeder systems. Cable loss s more specifically evidenced by a decay of certain signal characteristics including, but not necessarily limited to, amplitude decay and frequency decay.
In order to compensate for such cable losses certain electronic components have been developed for inclusion in the broadband network communication system. Prevalent among such electronic components are equalizers and simulators. Equalizers are designed and structured to compensate for frequency and amplitude decay of signals transmitted over long distances of coaxial cable used in broadband networks, as set forth above. Simulators compensate for short spans of coaxial cable and effectively function as small pieces of coaxial cable. However, despite the concerted efforts to develop effective compensating electronic components, including equalizers, simulators, amplifiers, etc., present manufacturers of these components have encountered problems with their operational design and/or manufacture. Such problems are most commonly demonstrated by inconsistent and unreliable performance in overcoming cable losses.
A review of prior art design and manufacturing standards of equalizers and like electronic components reveals that their notoriously inconsistent performance is most likely attributable to manually performing tuning and/or alignment procedures on these electrical components in order that such components meet intended or standard operational specifications dependent on their rating and intended use. In typical fashion, such required tuning and aligning procedures are done manually resulting in increased time and cost involved in the manufacturing of such components. More importantly, no matter how skilled or well trained the worker, human error is a significant factor in the accurate performance of the required tuning, and alignment procedures. Therefore production, in terms of quantity of products produced is significantly delayed and the products that are produced are at best inconsistent in terms of meeting recognized industry standards or specifications and performance characteristics.
Accordingly, there is a long recognized problem in the segment of the communication industry dealing with the operation and performance of CATV/MATV broadband network facilities, which is directly associated with the inability to consistently compensate for cable losses associated with the use of extended lengths of coaxial cable.
The present invention is directed to a method of designing and structuring an electronic component in a manner which eliminates the necessity for manually tuning and/or aligning the component during its manufacture. As set forth in greater detail hereinafter, the method of structuring the electronic component is particularly directed to an equalizer component of the type which is intended to compensate for xe2x80x9ccable lossxe2x80x9d invariably present when utilizing extensive lengths of coaxial cable in Cable Television/Master Antenna Television (CATV/MATV) broadband network facilities. However, it is emphasized that the method of the present invention is not limited to the structuring of an equalizer component, of the type set forth above. To the contrary, the method of the present invention, including what may generally be referred to as a xe2x80x9ctrial and errorxe2x80x9d technique, is applicable for the initial design and structuring of a variety of different electronic components.
It is of course recognized that the aforementioned cable loss is clearly evidenced and/or attributable to the decay of certain standard characteristics of the signals as they are being transmitted over the coaxial cable. When referring to equalizer components, the signal characteristics primarily involved include both frequency and amplitude. Accordingly, electronic equalizer components, as utilized in broadband network facilities of the type set forth herein, are conventionally designed and structured to compensate for frequency and amplitude decay of signals which, as set forth above, are transmitted over long distances of coaxial cable. Naturally, other electronic components serve similar compensatory functions, wherein such additional electronic components include simulators, amplifiers, etc. Accordingly, the method of the present invention is primarily, but not exclusively, directed to the structuring of equalizer components in a manner which compensates for the decay of predetermined signal characteristics, particularly including frequency and amplitude, of signals of known strength transmitted over known lengths of coaxial cable.
Further, the method of the present invention accomplishes the structuring of equalizer components in a manner which eliminates the necessity for the manual tuning and/or alignment procedures typically associated with the manufacture of equalizers and other electronic components. As will be recognized by those familiar with this segment of the communication industry, inconsistent operational performance of conventional equalizers is attributable, at least in large part, to human errors associated with the performance of the tunning and alignment procedures and/or to the methodology of the procedures actually used. Therefore, the unique method of the present invention provides for a design and structuring of an equalizer component, as well as other electronic components, in a manner which eliminates the necessity of performing any such manual tuning and/or alignment procedures and thereby eliminates or at least significantly reduces the inconsistency in the performance of such electronic components, as well as increasing production output and decreasing cost of manufacture when mass producing such components.
More specifically, the method of the present invention comprises the initial utilization and design of a predetermined base circuit which preferably comprises a bridge-T configuration. Such a bridge-T configured base circuit preferably incorporates a resistor series and shunt including a plurality of circuit components of pre-established resistance. These circuit components are selected to represent a pre-established resistance value which is dependent upon the estimated cable loss. The amount of cable loss is dependent upon the length of the coaxial cable as well as a variety of other associated operational factors. Once the base circuit is established, a signal is continuously processed through the base circuit. The processed signal is visually monitored, using its conventional monitoring equipment, in order to observe predetermined signal characteristics. In the present case of designing and structuring an equalizer component, both frequency characteristics and amplitude characteristics of the processed signal are monitored.
Thereafter, a trial and error technique is implemented, as indicated above, to the extent of providing a plurality of approximating circuit modifications to the base circuit for purposes of directly affecting the predetermined signal characteristics of the processed signal being monitored. As will be explained in greater detail hereinafter, each of the aforementioned circuit modifications are applied sequentially and are applied to the base circuit in a xe2x80x9cbalancedxe2x80x9d manner, as also explained hereinafter. The circuit modifications each include at least one circuit component, added to the base circuit, wherein the at least one circuit component of each modification is of a pre-established rating or value and wherein each component affects at least one of the predetermined frequency and amplitude characteristics of the signal being monitored.
Further, each of the circuit modifications represent an approximation of signal characteristic variance, wherein the addition of each circuit component included in each of the circuit modifications attempts to xe2x80x9cstabilizexe2x80x9d the particular predetermined signal characteristic, with the end purpose being to consistently produce stabilized processed signals. More specifically the end result of the method of the present invention, including the trial and error procedure implemented, is directed to the creation of an equalizer or like electronic component which consistently and efficiently compensates for cable loss. The accomplishment of a consistently performing equalizer is therefore evidenced by the transmission of a signal through the component which is visually observed to have eliminated the decay of the predetermined signal characteristics, including amplitude and frequency.
Once the signal has been xe2x80x9cstabilizedxe2x80x9d, further manual tunning and/or alignment of the component is no longer required to meet the intended industry standards and rating of the component.
The aforementioned trial and error procedure implemented in the method of the present invention is primarily due to the fact that the one or more circuit components included in the approximating circuit modifications are typically only available in standard ratings or values. Therefore, utilization of the aforementioned circuit components, each of which have a standard pre-established resistance and/or a standard pre-established capacitance and/or a standard pre-established inductance, provide only an approximation of the amount of variance required to modify the individual signal characteristics. As a result, each circuit modification is added to the base circuit for purposes of more closely accomplishing the amount of change needed for each of the predetermined signal characteristics, including frequency and amplitude, required for signal stabilization.
Finally, the method of the present invention comprises the application of one or more xe2x80x9ctransient influencesxe2x80x9d to the component for purposes of determining the final amount of variance still existing in each signal characteristic, which must be overcome before complete stabilization of the signal is established. As used herein, the term xe2x80x9ctransient influencexe2x80x9d may be more specifically defined, as a temporary modification applied to the equalizer, or certain circuit components thereof, which last only a brief period of time and which indicates the remaining amount of variance in each of the predetermined signal characteristics. Such transient influences are distinguishable from the one or more circuit components which define the approximating circuit modifications applied to the base circuit, wherein such circuit components and approximating circuit modifications in fact become a permanent part of the equalizer or other electronic component being structured. In more simplistic terms, each of the one or more transient influences applied to the equalizer component affects the signal being processed thereby and may be observed by a change in the predetermined signal characteristics, as the transient influence is applied and subsequently removed. This of course differs from the approximating circuit modifications in that such transient influences are removed from the component and do not become a part thereof.
The determination of the final amount of variance or modification which must be applied to the circuit is thereby determined by the one or more transient influences, as set forth above, wherein final modifications of the circuit can be performed to accomplish structuring of an equalizer or like electronic component which consistently processes a stabilized signal.